Leading Vertical Dampers

[Richard Brekne]

Hi Del, John and Andre'

I was thinking just of this kind of stuff, actually the lead I have for
inserting in hammers ala D.Stanwood. I had thought of adding about a gram of
weight to each damper.... perhaps tapereing off a bit in the end of the treble
section.

Also... John Ross... I didnt check this about the nodes... just assumed that
triple damper felfs were in order. The existing dampers were of the long sort,
but there were only 2 rather short wedges to each string in the bass. From the
tenor break upwards there were first 6 split wedges then flat dampers the rest
of the way. All of these were single long pieces. I had planned on spliting
these into two peice dampers, with the exception of the lowest two tenor notes.

I would imagine that a bit of nodal ringing is part of the problem here, as
Antares said this used to be popular. 

I just thought it might be a good idea to hedge my bets here. And I am curious
about the effects of useing a bit of lead in the damper heads. So I figured a
bit of lead, and tri piece bass dampers should do the job. 

Btw.. Springs were useable tension for sure...actually a bit on the strong
side... and centers are not particularilly tight. The old felt is off and was a
bit packed... but I have seen worse often enough.

Thanks for the good words of advice

RicB


 Delwin D Fandrich wrote:

>I should have added:
>
>Put the leads on before you strengthen any damper springs. After a bit of
>mass-loading you may not need stronger springs.
>
>Make sure you have the damper back-stop rail adjusted close in to prevent
>bouncing. It will feel just like a grand damper upstop rail set too high.
>
>Also, those elongated oval leads I used most recently started out about 18
>to 20 mm long and were about 10 to 12 mm in diameter at their waist.
>
>Del
>
>----- Original Message -----
>From: "Delwin D Fandrich" <pianobuilders@olynet.com>
>To: <pianotech@ptg.org>
>Sent: June 03, 2002 9:05 PM
>Subject: Re: Leading Vertical Dampers
>
>
>> Use the minimum amount of lead necessary to do the job. As I've written
>> before, I've used fisherman's leads which come in various sizes. Not
>being
>a
>> fisherman I don't know how these are sized. It probably wouldn't do you
>much
>> good anyway since the fish you have over there are probably different
>from
>> the fish we have here -- hence the different weapons used to go after
>them.
>>
>> You'll want a bit more mass in the bass than in the tenor and probably
>none
>> at all in the treble. Indeed, you might just treat the bass and see if
>that
>> does the trick. If you can conveniently obtain various sizes, get two or
>> three and experiment. My favorite so far are an elongated oval with a
>hole
>> in the middle. You have to remove the head to get them on, but that
>doesn't
>> take long.
>>
>> Don't forget a drop of glue -- something like PVC-e or plain old Elmer's
>> White Glue. It's just to prevent the possibility of buzzing later on.
>>
>> Del
>>
>>
>> ----- Original Message -----
>> From: "Richard Brekne" <richard.brekne@grieg.uib.no>
>> To: "PTG" <pianotech@ptg.org>
>> Sent: June 03, 2002 12:47 PM
>> Subject: Leading Vertical Dampers
>>
>>
>> > Hi folks
>> >
>> > I have decided to give this idea a try and see how it goes, and thought
>I
>> might
>> > both seek advice as to just how much lead to add to the dampers and at
>the
>> same
>> > time give a sort of before and after story of the action for everyones
>> > edification.
>> >
>> > This action is from an approximately 70 year old  Rønish full sized
>> upright.
>> > Damper felt is origional, dirty but not crusty......should actually do
>the
>> job
>> > well enough but doesnt. Springs are on the weak side for sure, and I
>think
>> I
>> > will have to change centers on the lot... but I will know that
>tommorrow.
>> In
>> > anycase the whole piano sings through the damper system quite a bit and
>> for a
>> > good long time. Seems pretty evenly distributed through the whole
>system
>> but
>> > the bass is a bit more active then the rest predictably enough. Still a
>> > noticeable drop in the problem when any section of the damped strings
>is
>> muted
>> > by hand.
>> >
>> > Anyways I thought about giving Dels advice a whirl on this one and am
>> asking
>> > for input as to how heavy the damper heads should be.
>> >
>> > RicB
>> >
>> > Richard Brekne
>> > RPT NPTF
>> > Griegakadamiet UiB
>> >
>>


Richard Brekne
RPT NPTF
Griegakadamiet UiB